Facile synthesis of hollow Cu(2)O octahedral and spherical nanocrystals and their morphology-dependent photocatalytic properties

Herein, we report that octahedral and spherical Cu(2)O samples with hollow structures are synthesized in high yield by reducing Cu(EDA)(2)(2+) complex with hydrazine. A series of experiments are carried out to investigate the factors which impact on the morphology of the Cu(2)O samples. It is observed that ethylenediamine (EDA) serves as a molecular template in the formation of hollow structure. Octahedral Cu(2)O with solid structure is prepared without EDA. When EDA is added, Cu(2)O sample with hollow structure is formed. Different morphologies of Cu(2)O such as spherical and octahedral could be obtained by adjusting the concentration of EDA and NaOH. The temporal crystal growth mechanism is proposed. Furthermore, the photocatalytic activities of the as-prepared Cu(2)O nanoparticles are evaluated by monitoring two dyes (methyl orange and congo red) using UV-visible spectrophotometer. Results show that the order of photocatalytic activity of Cu(2)O with different morphologies is as follows: hollow octahedral morphology > hollow sphere morphology > solid octahedral morphology. The hollow octahedral Cu(2)O nanoparticles would be a promising material on applications for photocatalytic degradation of organic pollutants.